A year ago the U.S. Food and Drug Administration also issued a warning that improper use of Neti pots and other nasal irrigation systems could lead to risky infections, including one with a brain-eating amoeba. Doctors believe an amoeba entered in through her upper nasal cavity and got into her bloodstream, eventually reaching her brain.

However, using tap water with a neti pot isn't safe, according to the US Food & Drug Administration (FDA).

But even though the woman used tap water, the odds were in her favor that she would have been fine. These sorts of infections are quite rare, but what's unique about this incident is that it's the "first case of Balamuthia mandrillaris brain infection suspected from nasal lavage", according to the case study, which was authored by Swedish scientists and the doctors who worked on the case, Cobbs included.

After a month of clearing her sinuses with the non-sterile water, a quarter-sized red rash appeared on the right side of her nose.

'We didn't have any clue what was going on, but when we got the actual tissue, we could see it was the amoeba'.

One year later, she had a seizure, and "lost cognition", according to the report. The CDC says it's possible that the amoeba may also live in water.

According to Dr. Zara Patel, a professor of otolaryngology at Stanford University, when people use contaminated water to rinse their nose and sinuses, they can be at risk for aggressive infections.

In the case report, the doctors said there was evidence of amoeba infection from neti pots before, but that they did not test the water their patients had been using, and so they could not be sure.

"It's such an incredibly uncommon disease it was not on anyone's radar that this initial nose sore would be related to her brain", Keenan Piper, a Swedish Medical Center employee and co-author of the study, told the newspaper. She entered surgery the next day. Repeat CT imaging demonstrated further haemorrhage into the original resection cavity.

The patient died about a month after finally receiving the correct diagnosis.

"She had not been boiling water, using sterile water or using sterile saline". There were three similar USA cases from 2008 to 2017. There have been over 200 diagnoses of the disease worldwide, 70 of which were in the United States, per the CDC.